EPL: results and potential applications

Abstract At the 65-nm technology node the first of the ‘next generation technologies’ will need to be introduced. There are several candidates, however one of the most promising from both a cost and performance point of view is electron projection lithography (EPL). For the 65-nm node EPL has a high potential especially for contact layers, whereas very high NA 157-nm optical tools need to be operated very close to their limits to achieve the resolution required. The second and more major challenge is to maintain a cost-effective process especially in cases where very few devices are produced by a mask set. This paper will show contact and line/space patterns of the dimensions we will see at the 65-nm technology node, printed in positive and negative resist systems on the 100-keV experimental EPL column at Nikon. We will demonstrate the extremely high resolution achieved on these features and discuss how this compares to the expected performance using 157-nm tools as derived by simulation. We will also discuss some potential roles for EPL technology, especially for products such as ASICs and system-on-a-chip technologies. In these devices a low number of wafers are used per mask set resulting in the mask cost being a major part of the manufacturing cost. In these cases the lower mask cost of EPL masks will provide a distinct advantage.